Long time no see

I've not slept for 36 hours so this maybe a little incoherent. Since my last post I've completed the 3D Printer project. On a personal note it only cost me £50 to complete as I've an array of junk parts to source from. The stepper drivers amazingly were only £1 each the A2 stainless rods were $15.50 and the rest was for the extruder as I didn't fancy building that. One of the steppers is from a 1990 era dialysis machine and boasts 0.8 degrees a step. I'm overrunning these steppers to 200% for speed Vs. moving mass and they require heat sinks else they bind up and loose steps (yee-haw).

Secondly; I've made the smallest watch in my collection (32x32x7mm). It's only on the second prototype so it's a little junky-funk. expect some images to appear in a day or so. The third prototype will incorporate Blue-tooth (BLE) a nRF8001 chip from nordic. I'm still wrestling with the ACI (Application Command Interface) Thats has some silly features like command credits. my C++ Fu isn't strong so understanding some of the *euch* Arduino examples is tricky but getting there slowly. It's probably going to just have a UART link between the watch and phone with a custom app that bangs all the notifications to it.

while( !BrainWorking ) {_nop;} 
work( );

DIY 3D Printer

Ach, Garr! Ok I'm going through project boxes like a beast. Also going through 6061 like boeing on a Friday before clocking off. I finally give in to 3D printers after grumbling and flaming at makerbots and the like, deciding to make my own for under £80. Here's a draft I've started making. I Started with the frame, rails and electronics. Electronics are undecided as I refuse to buy Ardweeeenoe or anything Atmel due to their ethics on many levels that I won't go into detail about. But I'll be basing the communication protocol on one of the popular platforms and translating the source as I go. I saw this great post using a 4550 that I have a box full of.
 
The most costly part I've seen is the heated bed. I'll be making it from home etched PCB with a soldermask bonded to tempered glass that luckily a friend had kicking about. It's the PCB or the 6 meters of Ni-chrome that I've had for 10 years. Yes I know, my biggest problem is not researching others but diving in. It's half the fun, right?

Ok, I gave in to buying an extruder that is half the project cost as the part cost equals the final cost of £33. The individual parts cost £30 minus machining and a stepper, plus the true and tested design.

This is a bit of a rant I know. But the prices and markup of even the modern kickstarter printers are silly, well silly for someone who enjoys making mechanical devices.
 
For the stepper motors I may steal some from the CNC mill as I found that the ones that I thought could be used were too high a voltage for my drivers (134Ohm). They'll probably work but I want some reliability on not slipping steps. I found a nice Japan Servo Co.LTD 0.9 degree from some old medical equipment (a pump from a dialysis machine) that's 7.6 Ohm, but only the one, this maybe able to be compensated in firmware? This £80 Project may become £116 If I need 4 motors. 3 I'm sure will suffice with only one on the Z-axis with a timing belt to the opposite thread screw.

I find making a quick sketchup of the device will allow me to obtain materials at random and not necessarily in order. Example ordering 4x8*880 long stainless bar and calculating that the Y + X length * 2 = 878mm.